1. Field of the Invention
This invention relates to a brake control method for a motorcycle and a brake control apparatus for a motorcycle which includes a front master cylinder, a front wheel cylinder hydraulically connected to the front master cylinder, a rear master cylinder and a rear wheel cylinder hydraulically connected to the rear master cylinder.
2. Description of the Prior Art
For example, in the brake control apparatus for a motorcycle disclosed in the Japanese Patent Official Gazette No. 71962/2000, the front master cylinder is hydraulically connected both to the front wheel cylinder and to the rear wheel cylinder through a normally open electro-magnetic changeover valve. Accordingly, when the front master cylinder is operated, brake fluid is supplied both to the front wheel cylinder and to the rear wheel cylinder. Thus, considerable brake fluid is required from the front master cylinder. Accordingly, the opening of the outlet port of the front master cylinder should be rather large. A large input to the brake hand lever of the front master cylinder is required for applying normal brake force.
In a brake control apparatus for a motorcycle disclosed in Japanese Patent Opening Gazette No. 71963/2000, when only the rear master cylinder is operated, brake fluid is discharged from the front master cylinder with the actuation of the hydraulic pressure pump and it is supplied to the front wheel cylinder. At that time, when the brake hand lever is actuated for operating the front master cylinder, the hand lever stroke becomes shorter than the hand lever stroke at the time when only the front master cylinder is operated, since some brake fluid is already discharged from the front master cylinder. Accordingly, the stroke of the brake lever is variable, and so the lever feeling in the driver""s hands is poor, or not so good.
Accordingly, it is the object of the invention to provide a brake control method for motorcycle and brake control apparatus for motorcycle in which the hand lever feeling when actuating the front master cylinder is always good, and one wheel cylinder connected to one master cylinder is associated or interlockingly actuated with the actuation of the other wheel cylinder connected to the other master cylinder.
In accordance with an aspect of this invention, a brake control method for a motorcycle is provided which includes a front master cylinder, front wheel cylinder means hydraulically connected to said front master cylinder and a rear master cylinder, rear wheel cylinder means hydraulically connected to said rear master cylinder and a hydraulic pressure pump. The improvement resides in the fact that when only said front master cylinder is operated, brake pressure fluid is supplied to said front wheel cylinder means and said fluid pressure pump is driven to supply discharging pressure fluid to said rear wheel cylinder means, and when only said rear master cylinder is operated, brake pressure fluid is supplied only to said rear wheel cylinder means.
In accordance with another aspect of this invention, a brake control method is provided for a motorcycle which includes a front master cylinder, one front wheel cylinder hydraulically connected to said front master cylinder, a rear master cylinder, a rear wheel cylinder hydraulically connected to said rear master cylinder and another front wheel cylinder hydraulically connected to said rear master cylinder and a hydraulic pressure pump. The improvement resides in the fact that when only said front master cylinder is operated, brake pressure fluid is supplied to said one front wheel cylinder and said fluid pressure pump is driven to supply discharging pressure fluid to said rear wheel cylinder, and when only said rear master cylinder is operated, break pressure fluid is supplied to said rear wheel cylinder and said other front wheel cylinder.
In accordance with a further aspect of this invention, a brake control apparatus for a motorcycle is provided which includes a first electro-magnetic changeover valve apparatus connected to a conduit between a front master cylinder and front wheel cylinder means, a second electro-magnetic changeover valve apparatus connected to a conduit between a rear master cylinder and a rear wheel cylinder, hydraulic reservoir means for reserving brake fluid discharged from said front wheel cylinder means and said rear wheel cylinder, and a hydraulic pressure pump the inlet port side of which is connected to said hydraulic reservoir means and the outlet port side of which is connected to said front master cylinder side and said rear wheel cylinder side. The improvement resides in the fact that a first association electro-magnetic changeover valve is arranged between said rear master cylinder and said outlet port side of said hydraulic pressure pump, said first association electro-magnetic changeover valve having normally the communicating state, a second association electro-magnetic changeover valve is arranged between a conduit portion between rear master cylinder and said first association electro-magnetic changeover valve, and the sucking inlet port side of said hydraulic pressure pump; said second association electro-magnetic changeover valve having normally the cutout state. When said front master cylinder is operated, said first association electro-magnetic changeover valve and second association electro-magnetic changeover valve are changed over from the communicating state to the cutout state, and from the cutout state to the communicating state, respectively, and accordingly said hydraulic pressure pump is driven.
In accordance with a still further aspect of the invention, a brake control apparatus for a motorcycle is provided which includes a first electro-magnetic changeover valve apparatus arranged between a front master cylinder and one front wheel cylinder, said first electro-magnetic changeover valve apparatus normally communicating said front master cylinder with said one front wheel cylinder, and cutting off said front wheel cylinder from a front hydraulic reservoir. A second electro-magnetic changeover valve apparatus is arranged between a rear master cylinder and a rear wheel cylinder, said second electro-magnetic changeover valve apparatus normally communicating said rear wheel cylinder with said rear master cylinder, and cutting off said rear wheel cylinder from a rear hydraulic reservoir, and including a hydraulic pressure pump the sucking inlet port side of which is connected to said front and rear hydraulic reservoirs, and the discharging outlet port side of which is connected to said rear master cylinder side and to said front master cylinder.
The improvement resides in the fact that a third electro-magnetic changeover valve apparatus is arranged between said rear master cylinder and another front wheel cylinder different from said one front wheel cylinder, said third electro-magnetic changeover valve apparatus normally communicating said different front wheel cylinder with said rear master cylinder, and cutting off said different front wheel cylinder from said rear hydraulic reservoir. A first association electro-magnetic changeover valve is arranged between said rear master cylinder and the outlet port side of said hydraulic pressure pump and said first association electro-magnetic changeover valve has a normally communicating state. A second associated electro-magnetic changeover valve is connected to a conduit connecting said rear master cylinder and said first associated electro-magnetic changeover valve, with the discharging port side of said hydraulic pressure pump. Said second associated electro-magnetic changeover valve normally has the cutoff state, and when said front master cylinder is operated, said first associated electro-magnetic changeover valve and said second associated electro-magnetic changeover valve are changed over from the communicating state to the cutoff state and from the cutoff state to the communicating state respectively, and said hydraulic pressure pump is driven.
In accordance with a further aspect of the invention, a brake control apparatus for a motorcycle is provided which includes a first electro-magnetic changeover valve apparatus arranged between a front master cylinder and front wheel cylinder means, said first electro-magnetic changeover valve apparatus communicating said front master cylinder with said front wheel cylinder means, and cutting off said front wheel cylinder means from a front hydraulic reservoir. A second electro-magnetic changeover valve apparatus is arranged between said rear master cylinder and said rear wheel cylinder, said second electro-magnetic changeover valve apparatus communicating a rear wheel cylinder with said rear master cylinder, and cutting off said rear wheel cylinder from a rear hydraulic reservoir, and a hydraulic pressure pump is provided with the sucking port side thereof connected to said front and rear hydraulic reservoirs, and the discharging port side of which is connected to said rear master cylinder side and to said front master cylinder side. The improvement resides in the fact that a third electro-magnetic changeover valve apparatus is arranged between said rear master cylinder and another front wheel cylinder different from the one front wheel cylinder, said third electro-magnetic changeover valve apparatus normally cutting off said different front wheel cylinder from said rear master cylinder, and cutting off said different front wheel cylinder from said rear hydraulic reservoir. A first associated electro-magnetic changeover valve is arranged between said rear master cylinder and the discharging port side of said hydraulic pressure pump, said first association electro-magnetic changeover valve having normally the communicating state. A second associated electro-magnetic changeover valve is connected to a conduit connecting said rear master cylinder and said first associated electro-magnetic changeover valve, with the discharging port side of said hydraulic pressure pump, said second association electro-magnetic changeover valve taking normally the cutoff state. When said front master cylinder is operated, said first associated electro-magnetic changeover valve and said association electro-magnetic changeover valve are changed over from the communicating state to the cutoff state and from the cutoff state to the communicating state, respectively and said hydraulic pressure pump means is driven.
The foregoing and other objects, features, and advantages of the present invention will be more readily understood upon consideration of the following detailed description of the preferred embodiments of the invention, taken in conjunction with the accompanying drawings.